Bonding and joining technology is fundamental in the manufacture of a wide variety of electronic assemblies. Power modules are examples of one type of electronic assembly in which forming robust bonds between the various components can be challenging. Power modules typically include electronic components that have high power losses in terms of heat, such as semiconductor dies that include power transistors, diodes, and the like. These modules may be part of a more extensive electronic system responsible for controlling speed and torque of electrical loads like motors.
Typically, power modules include a thermal stack that comprises multiple dies, e.g., semiconductor dies, bonded to a high power substrate, such as a Direct Bonded Copper (DBC) substrate or an Active Metal Brazing (AMB) substrate, which is bonded to a heat sink. The assembly of a substrate(s) with a die(s) and/or a heat sink(s) usually employs conventional bonding and joining technologies such as soldering, brazing, or high pressure sintering. These technologies, however, have several issues. First, soldering, brazing, and high pressure sintering each expose the entire electronic assembly to some form of bulk heating, e.g., reflow ovens for solder, which substantially heats the die(s) to temperatures that can detrimentally affect die performance and reliability. Second, solder joints often rapidly degrade at the relatively high module temperatures achieved during normal operation of power modules. Third, although brazing and high pressure sintering produce bonding joints that are more resilient to relatively high module temperatures, both brazing and high pressure sintering use non-ambient pressure conditions during processing which can be costly. In particular, brazing typically forms bonding joints under a vacuum and high pressure sintering typically forms bonding joints at pressures of about 30 MPa or greater. In addition, the higher pressures used during high pressure sintering can cause the dies to crack, resulting in lower power module production yields.
Accordingly, it is desirable to provide methods of bonding components for fabricating electronic assemblies by forming robust bonding joints, and electronic assemblies fabricated by such methods. Additionally, it is also desirable to provide methods of bonding components for fabricating electronic assemblies that are less costly, production friendly, and/or do not detrimentally affect die performance and reliability, and electronic assemblies fabricated by such methods. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.